DESCRIPTION (From applicant's abstract): The aims are to assess the population burden of occupational exposures in the prevalence of chronic obstructive pulmonary disease (COPD) and to estimate the impact of selected occupational risks on the severity of progression of COPD. COPD is common and costly. The contribution of occupational risk factors to its prevalence and progression have not been well characterized. Better delineation of these associations has been identified as a priority area for study in the NIOSH National Occupational Research Agenda. A population sample of the continental United States of those aged 55-75, supplemented by an enriched sample in geographic "hot spots" identified by NIOSH through respiratory diseases mapping, will yield 2120 subjects, of whom 400 will have COPD defined by report of chronic bronchitis or emphysema without asthma. Structured telephone interviews will assess demographics, health status, smoking exposures, and occupational histories. High risk jobs will later be coded using a job matrix system independent of subject report of specific exposures. Two hundred of those with COPD, with over-sampling of those with greater severity, will be followed at 12-14 months to assess health status and health services utilization, as well as decrements in quality of life. This study will provide statistically powerful estimates of the occupational association with COPD. We should be able to identify a work-related RR of 1.35 which, coupled with an exposure frequency of 20 percent, would reflect a PAR percent of 6.5 percent. In the longitudinal study component, we should be able to detect a RR>2.1 for selected occupational risk factors as predictors of outcomes occurring in at least 10 percent of the group.